Semantic vs. word-form specific techniques in anomia treatment: A multiple single-case study

摘要

This study compared a semantic and a phonological/orthographic approach to the treatment of word-finding difficulties in a case-series of ten individuals with aphasia, using a cross-over design. The study aims to investigate whether one approach is generally more effective than the other or whether the effectiveness of the two treatments relates systematically to the nature of the underlying functional impairment within the framework of a modular single-word processing model. In both treatments, the main task was spoken naming of pictured objects with different types of cues. In the semantic approach, different aspects of the target semantic concept were used as a cue in picture naming, while in the word-form method, both phonological and orthographic information were provided as a cue. Treatment effects were assessed in terms of both short- and long-lasting effects on spoken picture naming accuracy in each participant after the end of each treatment phase. Here, both item-specific effects and a possible generalisation to untreated pictures were considered. In addition, the immediate effects of the phonological and the semantic prompts were analysed. With regard to the cue effects on immediate naming, the word-form specific cues proved stronger than the semantic cues. The semantic treatment phase on the other hand, produced more stable effects than the word-form specific phase in some participants. A direct relationship between specific treatment effects and underlying functional deficit pattern was not confirmed for all subjects, i.e. participants with post-semantic anomia benefited from the semantic approach and participants with semantic anomia benefited from the phonological/orthographic approach. In the discussion of the results different explanations are considered, including the importance of preserved functions which aphasic participants bring into the treatment, the possible acquisition of a conscious strategy, and the possible influence of order of treatment. The effects of the two treatments are interpreted with regard to their underlying functional mechanisms in a single-word processing model.